Improvement in mercury baths for photographic purposes



UNITED STATES PATENT OEEICE.

JOHN MOULSON, OF PHILADELPHIA, PENNSYLVANIA.

IMPROVEMENT IN MERCURY BATHS FOR PHOTOGRAPHIC PURPOSES.

Specication forming part of Letters Patent No. 8,335, dated September 2,1851.

To all whom t may concern:

Be it known that I, JOHN MOULSON, ot the city of Philadelphia and Stateof Pennsylvania, have invented a new process for the development,production, mercurialization, and vaporization of photograph anddaguerreotype impressions or images or representations of objects madeby the impression of light upon a metallic or other surface, by whichthe operation is rendered more easy, more certain, more regular, and itsproducts mo re beautiful than by any process now known, and which iseffected by means of my movable and moving lever-cup bath g and I dodeclare that the followingis a full and exact description thereof,reference being had to the accompanying drawings, and to the letters ofreference marked thereon.

The nature of my invention consists in the agitation of the mercury orother substances used immediately previous to the exposure of thephotograph impression to its iniiuence and upon a cooler surface thanthat of the mercu ry-cu p proper, which I generally expose to constantheat, throwing off of the said heated surface ot' the cup the mercury orother substance when n ot intended for use, thereby to coolit and toagitate it and to prevent its evaporation or vaporizati on when not inuse, all of which I am enabled to do by means ot my movinglevenfcup bathfor photographic purposes with or without my double-plate-holding slide.

To enable others skilled in the art to make and use my invention, I willproceed to describe its construction and operation.

I construct a box A, of four sides and a lid, Figure l, about thirteeninches high from a to b, or of any other length,the width from a to cbeing seven and a halt inches and the width from b to d six and a halfinches, all of which sides are to be finished to an even plane on thetop, upon which is placed the movable lid b df g, made to fit on eitherside up with the projecting pins m m m m, which fit into correspondingholes n n, risc., in the top ends of the side A and the side opposite.When the double-plate-holding slide is to be used, on the under side otthis top, near each edge o to g and d to f, are attached two cleats k k,which are made fast to it, and to correspond in thickness with thethickness of the doubleplate-holding slide h, Figs. I and 2, so that itmay be inserted between them and be readily movable, the pins nzy m m mpassingand projecting through them into the top edges of f the sidesabove named. Into an opening in this top is inserted a pipe e to carryoff surplus vapor at pleasure, and so fitted as to be removed with thelid when the camera-slide only is used upon this bath. Thedoubleplate-holding slide 7L, Figs. l and 2, being a frame of wood fromone-fourth to one inch in thickness, one moiety of which will closelycover the top of the box A, Fig. l, and fit closely and ply between thecleats 7c 7c, and made with two openings a and b, of different sizes, toreceive plates or pictures ot' sizes to correspond, which are supportedtherein by ledges t tall round the openings orbybrackets v in thecorners, when they are to be submitted to mercurialization, the.

At five inches 'from the bottom, at about midway of the side A, I insertinto an opening or hole at T the movable center pin or tube I3 of mylever-cup A, Fig. 13, so that it will be supported by the pendent hook Lor its equivalent and in such manner as that the lever-cup may bereadily removed from the bath. The center pin or tube E, Figs. 3 and 4,on the opposite side (it used) may be supported in like manner for thesame purpose; but if the cup be not made to be removed from the bath asimple hole or opening to fit in the side of the bath will be a sufficient support.

The side P is made so as to leave six and a half inches in space belowit for the motion ot' the tube C, Figs. I and 3, and the bottom edge ris rabbeted to receive the lip s of the plate F G H I, Fig. 3, for thepurpose of excluding the light. In pla-ce of this side being continueddown, there` may be suspended upon the tube C of the cup A an apron R,Fig. l, or its equivalent (or a slide) composed of paper or other lightmateria-Lbeing pierced at s to receive the pipe or tube C through it',and to be pendent thereon and of such dimensions as to further excludethe light from above the plate F G H I, for which purpose it maybe madeof a convex shape externally, so as to lap the perpendicular' corners ofthe bath, if necessary.

Fig. 3 is a cup A, about one and threefourths inches square (but notnecessarily square) and one inch deep, with a flat bottom, forcontaining mercury or other substances, placed on aperpendicularly-movable axis B E, or either of them, which axis, if madetubular, may project into the corners of the cup, as atlD P, or not, andof such length as to pass through the side or sides of the box A, Fig.1, at T, and so that it may be supported by the pendent hook L. Into oneside or corner of this cup, at right angles with the axis, is introducedthrough the ange Q, Fig. 4, (or otherwise,) a pipe or tube C, one-fourthinch or more in open diameter, for the purpose of letting off from thecup A the mercury or other substance, when not in use, to a coolersurface at the end Ct of the tube C; or the cup maybe elongated toanswer the same purpose. which tube may be also bent upward at itsexterior end a, which may be stoppered with the stopper IV, and itslength may be eight or nine inches, or more or less, and its insidebottom surface must correspond with the inside surface of the bottom ofthe cup A at its insertion therein, so that all the mercury or othersubstance placed therein will flow out of the cup into the tube on thedepression of the end a, and on the elevation of that end it may allliowinto the cup, the tube being preferably placed into the cup so thatthe end a is elevated about one inch (in twelve inches of length) abovethe plane of the bottom of the cup A.

The axles or center of motion of the cup A, Fig. C, may be varied and beplaced in any manner giving and admitting the movement of the tube orelongated cup perpendicularly, but must be so arranged as that themercury or other substance used therein may flow from the heated surfaceof the cup to the cooler. surface of t-he tube or elongated cup, andvice versa, by elevating or depressing the exterior end of said cup, andmay be composed of any support forming a center of motion; or, morepreferably, the axle B may be tubular and may be attached to the side ofthe cup, as at e e, Fig. 4, at right angles,or nearly so, with the tubeC, and maybe closed at said attachment, and may project into the cup, asat p p, Fig. 3, for the purpose of admittinga thermometer-tube as nearto the mercury as possible, which is the object of the tubular axle, theaxle E, Figs. 3 and 4, being made in like manner for convenienceof useon either side, or it may be solid, or both may be solid if used withouta thermometer at this point. If the center of motion should not beconfined to the particular part of the cup, as above described, thetubular part can be retained, notwithstanding, or not, and the cup maybe suspended by any other center of motion giving the required movementof the mercury, ttc., as explained. In the interior of this bath or box,just above the plate F G II I and cup, is fitted a false bottom, ofpaper, in which is cut an opening large enough to admit the evaporatedmercury or other material to pass up. No part of this bottom ought tocover the cup A; but it is made to take a shape as near to that of theplate as possible, or be put in as near to it as possible, to excludethe light, for which purpose it is supported by cleats on all sides ofthe box beneath it.

The sizes, shapes, and measures here given of all parts are intended fora half-plate bath, and all or any of them may be varied, keeping to theprinciple of a free passage of the mercury, &c., from a heated to acooler surface, and vice versa, by means of my moving lever-cup or itsequivalent.

That I claim as my invention, and desire to secure by Letters Patent, is

l. My moving and movable lever-cup or its equivalent and bath forphotographic and daguerreotype purposes.

2.'Y The agitation of the mercury upon a cooler surface immediatelyprevious to its use in the heated cup (or part of it) for thedevelopment of photograph impressions by means of my movable lever-cupor its equivalent.

25. The lever-cup or elongated cup movable perpendicularly on an axis orcenterof motion, which center of motion need not be con lined to aparticular part of the cup, but it may be varied and placed in anymanner giving and admitting the movement of the cup, but must be soarranged as that the mercury or other substance may flow from the heatedsurface of the cup to the cooler surface of the tube or elongated cup,and vice versa, by elevating or depressing the exterior end of said cup.

4;. The balancing of said levercup or its equivalent on the center ofmotion whenever placed so that it Will remain stationary When the weightof the mercuryor other substance is let onto either end of it, that endcontaining the mercury or other substance used being held down.

. JOHN MOULSON.

Vitnesses:

F. E. MoULsoN, G. Z. FoNsEv.

